August j



(No Model.)

A. J. O'EHRING & H. H. WAIT.

GOMMUTATOR FOR HIGH VOLTAGE DYNAMOS.

No. 557,218. Patented Ma1.31, 1896.

UNITED STATES PATENT OFFICE.

AUGUST J. OEHRING AND HENRY H. XVAIT, OF CHICAGO, ILLINOIS, ASSIGN- ORSTO THE VESTERN ELECTRIC COMPANY, OF SAME PLACE.

COMMUTATOR FOR HIGH-VOLTAGE DYNAMOS.

SPECIFICATION forming part of Letters Patent No. 557,218, dated March31, 1896.

Application filed August Z0, 1895. Serial No. 559,947. (No model.)

To @ZZ whom, it may 00u/cern:

Be it known that we, AUGUST J. OEYHRING and HENRY H. VAIT, citizens ofthe United States, residing at Chicago, in the county of Cook and Stateof Illinois, have invented a certain new and useful Improvement inCommutators for High-Voltage Dynamos, (Case No. 4,) of which thefollowing is afull, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

Our invention relates to a commutator for dynamo-electric machines, ourobject being to provide a commutator of substantial and rigid mechanicalconstruction adapted for high -pressure dynamos and which can be readilyinspected and cleaned,all places where dirtmight collect being readilyaccessible.

In accordance with our invention we provide a disk, upon the face ofwhich the commutator-segments are mounted, the disk being preferablyformed of thin layers of wood mounted upon a metallic support. Theradial extensions or arms of the commutator-segments are secured to thefront of the disk of insulating material thus formed by means of screws,which do not pass entirely through the disk, so that there are no pointsupon the rear of the disk which are in electrical connection with thecircuit of the machine. Between the radial arms of thecommutator-segments are provided blocks of slate, which prevent suchflashing as may occur from doing any injury to the insulating materialon which the bars are supported. The spaces between thecommutator-segments are uniilled, and, due to the rotation of thearmature,`blasts of air are forced through the spaces between thesegments, which serve to blow out the sparks at the brushes and toprevent dirt from collecting between the segments. An annulus or ring issecured to the ends of the commutator-segments, thus maintaining thesegments against lateral displacement. The screws which secure thesegments to the support or disk being thus provided upon the front ofthe disk, they are readily accessible from the front and may betightened at any time, while the segments may be removed individ uallyfor repair. Furthermore, there are no hidden surfaces where dirt cancollect or where the insulation can deteriorate unobserved.

XVe will describe our invention by reference to to the accompanyingdrawings, in

which- Figure l is a view in cross-section of the commutator ofourinvention. Fig. 2 is a partial view thereof in elevation.

The support or spider a is mounted upon V6o the plate c preferably bymeans of a number of machine-screws c adapted to pass through the diskand engage tapped holes provided in the plate a and by a number ofwood-screws c2 passing through a hole provided in the plate screwinginto the wooden disk. the front of the disk c is preferably provided athin layer of mica d, and upon this rest the radial arms e of thecommutator-segments c, the arms being secured to the face of the disk bymeans of screws f f f2. thus accessible from the front and may bereadily removed at any time to remove a particular segment. The screws fj" f2 do not extend completely through the disk, so that there are nometallic portions upon the rear 8o of the supporting-disk electricallyconnected with the circuit of the machine. Between the radial arms e',as shown in Fig. 2, are provided blocks of slate g g, which are driveninto the tapering spaces between the radial arms, pins g' g preferablybeing employed for preventing the withdrawal of the blocks due tocentrifugal force as the cominutator rotates. The free ends of thecommutatorseginents are secured to a ring or annulus h 9o by means ofscrews 71,', a number of dowelpins h2 h2 being also provided formaintaining the segments accurately in alinement. Between the annulus7L, which may be made of wood, and the ends of the commutator-seg- 9 5upon the face of which the commutator-segroo ments are mounted, but thedisk has usually been made of slate or other brittle substance Upon 7oThe screws are 7 5 in order that the insulating material may benon-inflammable; but such construct-ion, in which a disk of brittlematerial is employed, is objectionable, since the disk becomes broken bycentrifugal force and jarring.

The object of our invention is to form the disk of non-brittleinsulating substance, such as Wood, and to render the supportiniiammable when arcing occurs by interposing between the radial arms ofthe segments wedges of slate or similar non-infiammable material.

Having described our invention, what we claim as new, and desire tosecure by Letters Patent, is-

1. In a commutator, the combination with a disk of wood, of segmentssecured to the face of said disk by screws passing through the segmentsand into the disk, but not passing completely through the disk, wherebythere are no metallic portions upon the rear of the disk electricallyconnected with the circuit of the machine; substantially as described.

2. In a commutator, the combination with a disk of insulating material,of commutatorsegments individually secured to and supported upon theface of said disk, and an annulus or ring secured to the ends of saidsegments to maintain the same against lateral displacement;substantially as described.

3. In a commutator, the combination with a disk of wood or othernon-brittle insulating material, of commutator-segments the radial armsof which are secured to the face of said disk, and wedges of slate orother non-iniammable insulating material filling the spaces between saidradial arms and protecting the disk from the effects oi' sparking;substantially as described.

In witness whereof we hereunto'subscribe our names this 29th day ofJuly, A. D. 1895.

AUGUST J. OEHRING. HENRY Il. VAIT. Titnessesz J oHN W. SINCLAIR, XV.CLYDE JoNEs.

